TCI state determination method and apparatus

This application is the US national phase application of International Application No. PCT/CN2020/120766, filed on Oct. 14, 2020, the entire contents of which are incorporated herein by reference for all purposes.

The present disclosure relates to a field of mobile communication technologies, and particularly to a method and an apparatus for detecting a transmission configuration indicator (TCI) state, a terminal and a medium.

In a New Radio (NR) wireless communication system, communication frequencies in the very high frequency (VHF) band may be used, such as frequency range (FR) 2. Since the high frequency channel attenuates rapidly, in order to ensure the coverage, it is necessary to use beam-based transmission and reception.

When the network device has multiple transmission and reception points (TRPs), the network device may use the multiple TRPs to provide services for the terminal, including using the multiple TRPs to send the physical downlink control Channel (PDCCH) to the terminal. In the traditional method, when the network device uses a TRP to send the PDCCH to the terminal, and a TCI state is configured for the control resource set (CORESET), then the TCI states of the search space sets associated with the CORESET are all the same as the TCI state of the CORESET.

When the method of repeatedly sending the PDCCHs with multiple TRPs is used, it is equivalent that the terminal needs to use beams corresponding to different TCI states to receive PDCCHs sent by different TRPs, and these multiple PDCCHs may come from the same or different search space sets (SS Sets). How to indicate the TCI states of the search space sets is a problem that needs to be solved.

According to an aspect of the present disclosure, a method for determining a TCI state is provided. The method is applied in a terminal, and the method includes:

According to another aspect of the present disclosure, a method for determining a TCI state is provided. The method is applied in a network device, and the method includes:

According to another aspect of the present disclosure, a terminal is provided. The terminal includes:

According to another aspect of the present disclosure, a network device is provided. The network device includes:

According to another aspect of the present disclosure, a computer-readable storage medium is provided. Executable instructions are stored in the computer-readable storage medium, and the executable instructions are loaded and executed by the processor to implement the method for determining the TCI state described above.

According to another aspect of the present disclosure, a computer program product is provided. Executable instructions are stored in the computer program product, and the executable instructions are loaded and executed by the processor to implement the method for determining the TCI state described above.

According to another aspect of the present disclosure, a chip is provided. The chip is configured to implement the method for determining the TCI state described above.

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

In all the following embodiments of the present disclosure, although different steps are numbered by numbers, these numbers are only for the purpose of making the text clearer, not for limiting the execution order of the steps and time slots. limited. In all the embodiments of the present disclosure, these numbered steps can be implemented individually or in any combination; when these steps are implemented in any combination, their execution order is not limited by the numbered numbers, that is, they can be performed in any order.

shows a block diagram of a communication system provided by an exemplary embodiment of the present disclosure. The communication system may include: an access networkand a terminal.

The access networkincludes several network devices. The network devicemay be a base station, which is a device deployed in the access network to provide a wireless communication function for the terminal. The base station may include various forms of macro base station, micro base station, relay station, access point and so on. In systems using different radio access technologies, the names of devices with base station functions may vary. For example, in LTE systems, they are called eNodeBs or eNBs; in 5G NR systems, they are called gNodeBs or gNBs. As communication technology evolves, the description of “base station” may change. For the convenience of description in the embodiments of the present disclosure, the above-mentioned apparatuses for providing a wireless communication function for the terminalare collectively referred to as network devices. In vehicle networking communication, the network device may also be a vehicle terminal.

The terminalmay include various handheld devices, in-vehicle devices, wearable devices, computing devices or Internet of Things (Internet of Things, IoT) devices or Industrial Internet of Things (IIoT) devices or other processing equipment connected to wireless modems, and various forms of user equipment, mobile stations (Mobile Station, MS), terminal devices, and so on. For the convenience of description, the devices mentioned above are collectively referred to as terminals. The network deviceand the terminalcommunicate with each other through some air interface technology, such as a Uu interface.

The technical solutions of the embodiments of the present disclosure can be applied to various communication systems, for example, a frequency division duplex (Frequency Division Duplex, FDD) system, a time division duplex (Time Division Duplex, TDD) system, an advanced long term evolution (LTE-A) system, a New Radio (NR) system, an evolution system of the NR system, a LTE-based access to Unlicensed spectrum (LTE-U) system, a NR-U system, a Universal Mobile Telecommunication System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, Wireless Local Area Networks (WLAN), Wireless Fidelity (WiFi), a next-generation communication system or other communication systems, etc.

Generally speaking, traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communication, but also support, for example, Device to Device (Device to Device, D2D) communication, Machine to Machine (M2M) communication, Machine Type Communication (MTC), Vehicle to Vehicle (V2V) communication and Vehicle to Everything (V2X) systems, etc. Embodiments of the present disclosure can also be applied to these communication systems.

The present disclosure proposes a method for indicating a transmission configuration indicator (TCI) state of a search space set, so that a terminal can determine respective TCI states corresponding to PDCCHs transmitted by multiple transmission and reception points (TRPs), thereby improving the success rate of receiving downlink control information (DCI) signaling.

shows a flowchart of a method for determining a TCI state provided by an embodiment of the present disclosure. This embodiment is exemplified by the method being executed by a terminal, and the method includes followings.

At step, an indication signaling is received.

The terminal receives the indication signaling sent by the network device. The indication signaling is at least one of a radio resource control (RRC) signaling, a medium access control (MAC) signaling, and a DCI signaling.

At step, N TCI states corresponding to a search space set (SS set) of the terminal are determined according to the indication signaling, where N is a positive integer.

The terminal determines N TCI states corresponding to the search space set of the terminal according to the indication signaling, where N may be one, or two or more than two.

To sum up, through the method provided in this embodiment, when the network device uses multiple TRPs to send PDCCH services for the terminal, when different SS sets of the same CORESET correspond to different TRPs, or different PDCCH candidates of the same SS set correspond to different TRPs, or one SS set corresponds to multiple CORESETs, a method for indicating TCI states of different SS sets or different PDCCH candidates is proposed, so that the terminal can receive the DCI sent on the corresponding PDCCH resource block according to the correct TCI state, to improve the decoding success rate of DCI.

The above-mentioned indication signaling may adopt an explicit configuration mode or an implicit configuration mode.

For the explicit configuration mode:

In an optional embodiment based on, the above-mentioned stepmay be alternatively implemented as step, as shown in.

At step, configuration of the search space set is read from the indication signaling, in which the configuration of the search space set includes: TCI state identifiers of N TCI states corresponding to the search space set.

When there are one or more search space sets, the terminal reads the configuration of each search space set from the indication signaling, and the configuration of the ith search space set includes the TCI state identifiers of Ni TCI states corresponding to the ith search space set, where i is a positive integer.

For example, the TCI state identifiers include: absolute identifiers of the TCI states.

For example, the network device sends a Radio Resource Control (RRC) signaling to the terminal, and the RRC signaling configures 64 TCI states for all CORESETs sending PDCCH, then the TCI state identifiers used for the search space set has one or more values taken from 0 to 63. That is, each TCI state also needs to be indicated by 6 bits (because there are 64 TCI states). As shown in Table 1:

For example, the TCI state identifiers include serial numbers of M TCI states corresponding to one CORESET to which the search space set belongs, sorted by numbers, where M is an integer greater than 1.

For example, the network device sends the RRC signaling to the terminal. The RRC signaling configures 64 TCI states for the CORESETs to which the search space sets belong. Then the network device sends the MAC signaling to the terminal. The MAC signaling configures the CORESET to which the search space set belongs with TCI #3, TCI #5, then the serial number of the TCI states corresponding to the search space set can be new TCI #0 (corresponding to TCI #3) and/or new TCI #1 (corresponding to TCI #5). That is, each TCI state only needs 1 bit to indicate, because the CORESET to which the search space set belongs is only configured with 2 TCI states.

To sum up, in the method provided in this embodiment, the network device sends the explicitly configured indication signaling to the terminal, so that when the network device uses multiple TRPs to send the PDCCH service for the terminal, the method for indicating the TCI states of different search space sets is proposed. The method enables the terminal to receive the DCI sent on the corresponding PDCCH resource block according to the correct TCI state, thereby improving the decoding success rate of the DCI.

For the implicit configuration mode:

The TCI state of each search space set has a default mapping relationship with the TCI state corresponding to the CORESET to which it belongs.

Mapping mode one (in no particular order):

In an optional embodiment based on, the above-mentioned stepmay be alternatively implemented as stepand step, as shown in.

At step, one or more CORESET to which the search space set belongs and a TCI state corresponding to each CORESET are read from the indication signaling.

The same search space set may belong to one or more CORESETs.

Taking the search space set corresponding to multiple CORESETs as an example, the terminal reads at least two CORESETs and the TCI state corresponding to each CORESET from the indication signaling. Optionally, each CORESET corresponds to one TCI state.

At step, the TCI state corresponding to each CORESET to which the search space set belongs are determined as the TCI states corresponding to the search space set.

The terminal determines the TCI states corresponding to respective CORESETs to which the same search space set belongs as the TCI states corresponding to the search space set.

Mapping Mode Two:

In an optional embodiment based on, the above-mentioned stepmay be alternatively implemented as stepand step, as shown in.

At step, M TCI states corresponding to the CORESET to which the search space set belongs are read from the indication signaling, where M is a positive integer.

The same search space set may belong to one or more CORESETs. Each CORESET corresponds to M TCI states. It should be noted that the number of TCI states corresponding to each CORESET is the same or different. When there are at least two CORESETs corresponding to different TCI states, the number of TCI states corresponding to the i-th CORESET is M.